Sparse look up usage

LavanyaRamesh007 · Post by **LavanyaRamesh007** » Mon Jul 28, 2008 4:45 am

Since the reference data is too big I am planning to use Sparse look up.. Before that should i have to confirm this by checking the RAM size???
Is it that only when RAM is too small to fit reference data we got to go for Sparse look up...??

ray.wurlod · Post by **ray.wurlod** » Mon Jul 28, 2008 3:41 pm

No, you can use sparse lookup at any time, whether or not you have checked the memory. It is the least efficient option, and is intended for use only when the reference data set is known in advance to be too large to fit in virtual memory. Note that sparse lookup can not be selected dynamically, so forget any idea you may have had about checking memory at run time within DataStage.